Violations of motor vehicle laws, such as speeding laws, may become an increasing concern as highways become more crowded with ever increasing numbers of vehicles. Electronic systems for monitoring vehicles are described in U.S. Pat. No. 6,107,917 to Carrender et al., entitled Electronic Tag Including RF Modem for Monitoring Motor Vehicle Performance With Filtering; U.S. Pat. No. 6,124,810 to Segal et al., entitled Method and Apparatus for Automatic Event Detection in a Wireless Communication System; and U.S. Pat. No. 6,223,125 to Hall, entitled Collision Avoidance System.